Devices are known for delivering implantable endoprostheses, such as stents, into a body vessel. Devices of this kind often include a proximal portion that remains external to the body vessel during use and a distal portion that is inserted into the body vessel (e.g., through an incision). The proximal portion typically provides for manipulation of the device during use. The distal portion often includes an outer sheath slidably positioned about an inner member with an endoprosthesis disposed therebetween. Generally, the distal portion of the device is advanced through the body vessel to a treatment site (e.g., a stenosis or aneurysm). The outer sheath can then be retracted to allow the endoprosthesis to expand to engage a wall of the body vessel at the treatment site. Thereafter, the device is removed leaving the endoprosthesis engaged with the body vessel.